Perfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been widely used in various industrial applications, consumer products, and firefighting foam. PFAS are known to persist in the environment and can contaminate drinking water sources, posing potential health risks to humans.
Types of PFAS
There are many types of PFAS, including:
- Perfluoroheptanoic acid (PFHpA)
- 4,8-dioxa-3H-perfluorononanoic acid (ADONA)
- Perfluorohexanesulfonic acid (PFHxS)
- 9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
- Perfluorohexanoic acid (PFHxA)
- Hexafluoropropylene oxide dimer acid (HFPO–DA) (GenX)
- Perfluorononanoic acid (PFNA)
- Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
- Perfluorooctanesulfonic acid (PFOS)
- Perfluoro(2-ethoxyethane) sulfonic acid (PFEESA)
- Perfluoro-3-methoxypropanoic acid (PFMPA)
- Perfluoro-4-methoxybutanoic acid (PFMBA)
- Perfluorobutanesulfonic acid (PFBS)
- Perfluorobutanoic acid (PFBA)
EPA Method 537.1
The United States Environmental Protection Agency (EPA) has established a method for detecting PFAS in drinking water, known as EPA Method 537.1. This method uses solid-phase extraction followed by liquid chromatography/mass spectrometry to detect the presence of four PFAS: perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUnA).
UCMR Testing
The EPA has implemented a national program to monitor drinking water for PFAS, known as the Unregulated Contaminant Monitoring Rule (UCMR). The UCMR testing began in January 2023 and will continue through December 2025. More than 10,000 water systems are participating in this program, with approximately 800 systems serving as a representative sample for smaller systems.
What Do the Test Results Mean?
The test results from the UCMR program provide valuable information about the presence and levels of PFAS in drinking water sources across the country. The data will help determine whether certain contaminants are present at levels that pose health risks to humans.
What Happens After UCMR Testing?
After the UCMR testing is complete, the EPA may conduct an evaluation to determine whether to begin regulating some or all of the PFAS detected in drinking water sources. Utilities that test positive for PFAS will need to take steps to remove or reduce the contaminants from their systems.
Perfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been linked to potential health risks when present in drinking water. The EPA's UCMR program is working to monitor and regulate PFAS in drinking water sources across the country. By understanding the types of PFAS, the testing methods used to detect them, and what happens after testing, we can work together to protect public health and ensure that our drinking water is safe for consumption.
References
- EPA Method 537.1: Determination of Perfluoroalkyl Substances (PFAS) in Drinking Water by Liquid Chromatography/Tandem Mass Spectrometry
- Unregulated Contaminant Monitoring Rule (UCMR): Frequently Asked Questions